Evolutionary Biology and Appeals to Natural Teleology in Ethics

One way in which evolutionary biology may play a modest role in
metaethics is by raising difficulties for appeals to
natural teleology
in the attempt to account for ethical normativity.
Following Aristotle, philosophers have been intrigued by the natural
norms associated with what seem to be objective proper functions and
ends associated with living things. We speak of a defective
heart valve, for example, in connection with the idea of its proper
function, where this seems objectively grounded in facts about the life
of the kind of organism in question: if a type of structure has a
proper function in members of a given species, and this particular one
is failing to perform that function in normal circumstances, then we
can say that it is defective. And if we can apply these functional and
normative concepts at the level of physiology, it seems equally
possible to apply them at the level of psychology and behavior, as is
common in ethology when speaking of the functions of behavioral
patterns associated with fighting, fleeing, mating, and so on. Perhaps,
then, the same conceptual framework of natural proper functions, ends,
and associated evaluative claims applies equally to human life at the
level of thought, feeling and behavior.

Indeed, some philosophers have thought that this might be precisely
the way to provide an objective and naturalistic account of ethical
normativity, with ethical judgments about an individual's
character traits, for example, being a special case of evaluative
judgment associated with natural functional claims. Just as a heart
valve may be defective if it has properties that make it fail to
fulfill its function in the life of such organisms, so too a
person's will might be defective if it has properties (i.e.,
‘vices’) that make it fail to fulfill its function in the
life of human beings. This might seem to tie into the intuitively
attractive idea that virtues are excellences of character that promote
human flourishing, while vices are traits that inhibit our flourishing
(Foot 2001; Thompson 1995, 2008).

Evolutionary biology raises significant challenges to any such
approach to understanding ethics, though this is not as straightforward
as it might at first seem. Evolutionary biology does not automatically
undermine the very idea of proper functions and ends in biology, as
some have suggested. While neo-Darwinian evolutionary theory does
soundly reject any appeal to teleology in the process of evolution
itself, there is a large literature in contemporary philosophy of
biology defending the legitimacy of employing teleological concepts in
connection with adaptations. For example, we plausibly attribute to the
heart the proper function of pumping the blood (which is not
merely something it happens to do, as it happens to make a certain
distinctive noise), which occurs for the sake of circulating
the blood and distributing nutrients and removing wastes (a
teleological explanation for why the heart pumps the blood),
and so on. The natural selection background of adaptive traits is in
fact often at the heart of contemporary accounts of biological
functions and ends. (See the entry linked above for details.)

Nor are these accounts limited to the physiological or morphological
levels. On typical accounts of natural functions and ends, they extend
to the spheres of psychology and behavior in many animals. It is
plausible, then, to suppose that similar appetitive, emotional, and
other psychological dispositions in human beings have similar proper
functions; and if there are uniquely human psychological adaptations,
as evolutionary psychologists claim, then these plausibly have
biological functions as well. So the problem is not that the
application of teleological concepts in biology has been discredited by
Darwinism, or that it must be limited to physiology and cannot pertain
to psychology and behavior.

The problem with appeals to natural teleology in ethics is rather
that it is hard to see how we can employ teleological concepts in
non-arbitrary ways without appealing precisely to the evolutionary
causal histories that have given shape to and organized these
traits into coherent functional systems. We must, for example, be able
to distinguish non-arbitrarily between proper functions or ends and
mere accidents—even useful ones, since the concepts of proper
function and end are richer than that of a beneficial effect (even a
statistically common one). But if we want to speak non-arbitrarily of
the proper function of a trait or structure T, distinguishing this from
other potentially useful but accidental effects that cannot properly
figure into teleological explanations of T, then it seems unavoidable
(or so many have argued) to look in some way to the distinction between
the effects that figured into the natural selection history that shaped
the trait (e.g., pumping rather than noisemaking, in the case of the
heart) and effects that did not. There are many versions of this
broadly “etiological” approach, many of which are more
complicated than just identifying functions individually with selected
effects. But there is a fairly broad agreement that some version of
this approach will be necessary in order to make non-arbitrary sense of
intuitive talk of what a trait T is for, i.e., what T does not
merely “function to” do but has it as its proper
function to do, which provides a certain kind of explanation (a
teleological one) of T and supports normative claims about tokens of
T.

This poses a difficulty for attempts to understand ethical
normativity in terms of natural teleology because it seems to undermine
the sort of welfare-based conception of natural teleology that would be
necessary for a teleological naturalist approach to ethics to get off
the ground. Recall that the reason such an approach might seem
attractive in thinking about ethics is that ethics plausibly has to do
with norms associated with human flourishing, and it might initially
appear that natural teleology also involves norms associated with
species-typical flourishing (Foot 2001). If, however, natural functions
and ends in living things are structured by special relations
established through the process of evolution through natural selection,
i.e., non-incidental relations between traits and a special subset of
their effects that figured into the selection process, then natural
teleology will not ultimately or generally be about the welfare or
flourishing of organisms (FitzPatrick 2000).

As discussed in section 2.2, the evolutionary principles according
to which organisms are put together and conditioned as functional
systems are not driven ultimately or generally by considerations of
organismic flourishing or need-satisfaction. They have instead
ultimately and generally to do (roughly) with whether a given trait T
does a better job of propagating copies of the alleles A that tend to
result in its expression, as compared with alternative traits T*
produced by rival alleles A*, resulting in greater proportional
representation of A in the gene pool in successive generations. This
will often favor traits that promote the welfare of the organisms in
question, but often it will not; and even where it does, it is only
because of the ultimate effect on the relevant germ-line gene
propagation, not because of the significance of welfare as such, which
will be irrelevant in cases where it doesn't also contribute
relevantly to gene propagation, e.g., where it doesn't also
promote reproductive output (Dawkins 1982).

For these reasons, a welfare-based conception of natural
functions and ends is problematic. Suppose, as suggested above, that an
organism's teleological profile is indeed shaped by the facts of
the evolutionary history that ultimately explain how it was put
together as the organized functional system it is. In that case,
organisms will be teleologically organized ultimately and generally
toward the end (roughly) of passing along germ-line copies of their
genes as well as or better than rival conspecifics (this being the
unifying effect non-incidentally promoted by all of the
organism's proper-functional traits)—rather than toward the
end of flourishing as such in any richer, intuitive sense.
Since this has little to do with what we would think of as ultimately
and generally relevant to ethical normativity when applied to
the human case, it seems doubtful that the normative framework provided
by natural teleology can be of any help in thinking about the normative
framework of ethics (FitzPatrick 2000; on the other side, see Casebeer
2003 for a defense of such an approach, and Lott 2012 for a defense of Foot and Thomson against FitzPatrick's objections).

It could conceivably have been different. If natural teleology were
the result of benevolent intelligent design with human flourishing in
view, as a kind of analogue of artificial teleology for a divine
designer, then we might be able to understand natural functions and
ends ultimately in terms of the good or flourishing of the organisms in
question. In that case, it might make sense to think of ethical norms
as a species of natural teleological norms as applied to the
reason-involving sphere of human life (practical deliberation, feeling,
choice and action). If, however, the true account of the structures of
functions and ends we find in living things is a result of evolution
rather than intelligent design, and we need to appeal to the
evolutionary history behind the assembly of those structures in order
to understand them as such, then the overall shape of natural teleology
will look very different, and it will hold out little hope for serving
as the basis of ethical normativity when applied to human life. This is
one way, then, in which evolutionary biology seems to have a clear and
direct bearing on certain philosophical projects in metaethics,
undermining approaches that once appeared promising but may no longer
be viable.

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